Most of the posts so far deal with the quality of meat, but in the Great Lakes you also have to be aware of health advisories restricting the consumption of fish due to contaminants in tissues. On the Milwaukee River it is recommended that you only eat 1 meal/month of chinook <30" long and 1 meal every 2 mo of chinook >30". I think the contaminant of concern in the Milwaukee River and Lk. Michigan is PCBs.

Check out the following web-site (Wisconsin DNR) for more information.
http://www.dnr.state.wi.us/org/water/fhp/fish/advisories/tables.PDF